THIS FOCUSES ON THE DEVELOPMENT OF A SOFTWARE TOOL TO TEST A PRIORI GLOBAL IDENTIFIABILITY OF LINEAR COMPARTMENTAL MODELS, A CLASS OF LINEAR DIFFERENTIAL EQUATION MODELS BASED ON MASS CONSERVATION PRINCIPLES AND THE MODELS MOST FREQUENTLY USED IN SAAM II. THE PROBLEM HAS BEEN SOLVED FOR A VERY LIMITED SET OF MODELS, BUT NO SOLUTION EXISTS IN THE GENERAL CASE. THE ALGORITHM WE ARE DEVELOPING IS BASED ON THE TRANSFER FUNCTION TOPOLOGICAL METHOD AND ON A COMPUTER ALGEBRA METHOD CALLED THE GRBNER BASIS. THE COMBINATION OF THESE TWO METHODS WILL RESULT IN A POWERFUL TOOL WHICH DECREASES THE COMPLEXITY AND THEN SOLVES THE SYSTEM OF NONLINEAR ALGEBRAIC EQUATIONS ASSOCIATED WITH THE A PRIORI GLOBAL IDENTIFIABILITY PROBLEM. THE ALGORITHM WILL DETERMINE FOR EACH PARAMETER OF THE MODEL IF THERE IS ONE, MORE THEN ONE BUT A FINITE NUMBER, OR AN INFINITE NUMBER OF SOLUTIONS. RFKA IS SUPPORTING THE INITIAL DEVELOPMENT OF A PROTOTYPE FOR THIS METHOD; THIS IS CURRENTLY BEING TESTED USING A VARIETY OF MODELS. AN R-01 HAS BEEN SUBMITTED TO SUPPORT THE FULL DEVELOPMENT AND IMPLEMENTATION OF THIS METHOD AS A MODELING TOOL IN SAAM II.